This invention relates generally to the field of drawing aids and more particularly to a device which is attachable to a drafting machine for use in applying symbols to a drawing.
There are a great number of stencil-type aids available to a draftsman who is required to repeatedly apply certain shapes and symbols to a drawing. These usually take the form of a draft square, for example, which is a square of clear plastic or the like having openings shaped to provide stencils of the various shapes required. A draftsman working on an electrical drawing requires a set of such templates while other sets are required for piping layouts, welding drawings and so on. The proper selection and placement of such templates takes up an undesirable amount of the draftsmans time and often they cannot be used effectively within the modern parallel-motion drafting machine.
Attempts have been made to provide drafting machine attachments which will aid in the application of symbols and such devices are suitable when a relatively small number of symbols or the like are to be applied to a drawing but a draftsman expected to turn out a variety of work with speed and accuracy generally finds such symbol-applying aids time-consuming and awkward to use. As a result, many draftsmen resort to stencils which are not attachable to the machine and these do little to assist in locating the place on the drawing to apply a particular symbol.